Dynamic region based application operations

ABSTRACT

Techniques are disclosed for a hybrid undo/redo for text editing, where non-linear undo and redo operations are performed across dynamic regions in a document and linear undo and redo operations are performed within the dynamic regions in the document. In an example, the hybrid undo/redo may be achieved by maintaining respective region offset values for the dynamic regions created in a document by the edits made to the document. In operation, the respective region offset values associated with the dynamic regions can be used to negate or otherwise counteract the effect of edits made in the dynamic regions.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims the benefit of PCTPatent Application No. PCT/CN2020/089056 filed on May 7, 2020 in theEnglish language in the State Intellectual Property Office anddesignating the United States, and the contents of which are herebyincorporated herein by reference in its entirety.

BACKGROUND

Many software applications (also referred to as “application software”,or simply “applications” or more simply “apps”) provide an edit functionwith which a user may make changes to a document. For example, such anedit function may allow a user to change existing content, add content,or delete content in a document. Many of these applications also supportundo and/or redo operations. In brief, an undo operation erases orundoes the last change made to a document, thus reverting the documentto an older state (a state prior to the last change to the document). Aredo operation reverses or negates the most recent undo operation.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key or essentialfeatures or combinations of the claimed subject matter, nor is itintended to be used to limit the scope of the claimed subject matter.

In accordance with one example embodiment provided to illustrate thebroader concepts, systems, and techniques described herein, a method mayinclude providing a data structure for a region of a document, the datastructure including a start value, an end value, and an offset valuethat define the region within the document. The method may also include,responsive to detection of a modification of content within the region,determining a count of the number of lines of the document within theregion, adjusting at least one of the start value, the end value, andthe offset value of the region to change an area of the region based onthe count of the number of lines, and pushing a record of themodification onto a stack of the region in response to the modificationof content within the region, the stack configured to receive elementsrepresentative of individual actions to be performed on content withinthe region of the document, so as to enable the modification to beundone or redone in a non-linear fashion.

In one aspect, the region is a first region and the method may alsoinclude, responsive to detection of a modification of content that addsor deletes at least one line within a second region of the documentlocated above the first region of the document, adjusting the offsetvalue of the first region to change an area of the first region based onthe modification of content within the second region.

According to another illustrative embodiment provided to illustrate thebroader concepts described herein, a system includes a memory and one ormore processors in communication with the memory. The processor may beconfigured to provide a data structure for a region of a document, thedata structure including a start value, an end value, and an offsetvalue that define the region within the document. The processor may bealso configured to, responsive to detection of a modification of contentwithin the region, determine a count of the number of lines of thedocument within the region, adjust at least one of the start value, theend value, and offset value of the region to change an area of theregion based on the count of the number of lines, and push a record ofthe modification onto a stack of the region in response to themodification of content within the region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.

According to another illustrative embodiment provided to illustrate thebroader concepts described herein, a method may include providing afirst data structure for a first region of a document, the first datastructure including a start value, an end value, and an offset valuethat define the first region within the document, and providing a seconddata structure for a second region of a document below the first region,the second data structure including a start value, an end value, and anoffset value that define the second region within the document. Themethod may also include, responsive to detection of a modification ofcontent within the first region, determining a count of the number oflines added or deleted in the first region, adjusting at least one ofthe start value and the end value of the of the first region based onthe modification of content within the first region, and adjusting theoffset value of the second region to change an area of the second regionbased on the count of the number of lines added or deleted in the firstregion.

In one aspect, the method may also include, responsive to detection ofthe modification of content within the first region, pushing a record ofthe modification onto a stack of the first region in response to themodification of content within the first region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the first region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages will beapparent from the following more particular description of theembodiments, as illustrated in the accompanying drawings in which likereference characters refer to the same parts throughout the differentviews. The drawings are not necessarily to scale, emphasis instead beingplaced upon illustrating the principles of the embodiments.

FIG. 1 is a diagram of an illustrative network computing environment inwhich embodiments of the present disclosure may be implemented.

FIG. 2 is a block diagram illustrating selective components of anexample computing device in which various aspects of the disclosure maybe implemented, in accordance with an embodiment of the presentdisclosure.

FIG. 3 is a schematic block diagram of a cloud computing environment inwhich various aspects of the disclosure may be implemented.

FIG. 4A is a block diagram of an illustrative system in which resourcemanagement services may manage and streamline access by clients toresource feeds (via one or more gateway services) and/orsoftware-as-a-service (SaaS) applications.

FIG. 4B is a block diagram showing an illustrative implementation of thesystem shown in FIG. 4A in which various resource management services aswell as a gateway service are located within a cloud computingenvironment.

FIG. 4C is a block diagram similar to FIG. 4B but in which the availableresources are represented by a single box labeled “systems of record,”and further in which several different services are included among theresource management services.

FIG. 5 is a block diagram showing example dynamic regions in a document,in accordance with an embodiment of the present disclosure.

FIG. 6 is a diagram of an example dynamic region data structure, inaccordance with an embodiment of the present disclosure.

FIG. 7 is a diagram of an example edit operation record, in accordancewith an embodiment of the present disclosure.

FIGS. 8A-8E show an example operation of dynamic region data structuresin processing edit operations performed during a document editingsession, in accordance with an embodiment of the present disclosure.

FIGS. 9A and 9B show an example deletion of a line in a document, inaccordance with an embodiment of the present disclosure.

FIG. 10 is a diagram of an example operation of dynamic region datastructures in processing a deletion of a line in a document, inaccordance with an embodiment of the present disclosure.

FIG. 11 is a diagram of an example operation of dynamic region datastructures in processing an edit of multiple lines in a document, inaccordance with an embodiment of the present disclosure.

FIGS. 12A and 12B show an example merge of two dynamic regions in adocument, in accordance with an embodiment of the present disclosure.

FIG. 13 is a diagram of an example operation of dynamic region datastructures in processing an undo operation, in accordance with anembodiment of the present disclosure.

FIG. 14 is a diagram of an example operation of dynamic region datastructures in processing another undo operation, in accordance with anembodiment of the present disclosure.

FIG. 15 is a flow diagram of an example process for processing amodification to a document, in accordance with an embodiment of thepresent disclosure.

FIG. 16 is a flow diagram of an example process for processing an undooperation, in accordance with an embodiment of the present disclosure.

FIG. 17 is a flow diagram of an example process for processing a redooperation, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Undo/redo operations supported by many existing applications enhanceuser-computer interaction by allowing a user to make changes to adocument knowing that the changes can be easily undone and redone. Theability to undo and redo changes made to a document instills in the userconfidence to make changes the user would not typically make byproviding a safety net.

Many conventional undo implementations are linear undo operations.Linear undo is typically implemented with a stack (e.g., a last in firstout (LIFO) data structure) that stores a history of all executedoperations. When a new operation is performed, this operation is placedor “pushed” on top of the stack. Therefore, only the last operationperformed (the operation at the top of the stack) can be removed or“popped” from the stack to be undone. The undo operation can be repeatedas long as the stack is not empty.

For example, suppose a user performs the sequence of operations A, B, C,D, and E. At the conclusion of these operations, the contents of thestack, from bottom to top, is A-B-C-D-E. Thus, the user is only able toundo operation E, which is at the top of the stack.

In other words, the user is unable to undo operation A, B, C, or Dbecause these operations are not at the top of the stack. For example,if the user wants to undo operation B, the user will first have to undooperation E, then operation D, and then operation C. After operation Cis undone, operation B will be at the top of the stack, and the userwill then be able to undo operation B. Hence, the linear characteristicof the linear undo. However, it may be that the user does not wantoperations C, D, and E undone. In this case, the user will beinconvenienced since the user will need to repeat (i.e., redo)operations C, D, and E after operation B is undone.

Concepts, devices, systems, and techniques are disclosed for a hybridundo/redo for text editing, where non-linear undo and redo operationsare performed across dynamic regions in a document and linear undo andredo operations are performed within the dynamic regions in thedocument. A dynamic region in a document defines a region or a portionof the document where one or more edits (interchangeably referred toherein as “changes” or “modifications”) have been made to the document.A region offset value associated with a particular dynamic region isused to maintain a record of the movement or shifting of the particulardynamic region within the document as a result of edits that involveline additions (insertions) and line reductions (deletions) made indynamic regions located above (i.e., higher than) the particular dynamicregion in the document. As such, the region offset value of theparticular dynamic region can be used to negate or otherwise counteractthe effect of such edits to the particular dynamic region (e.g., negatethe effect of the shifting of the particular dynamic region within thedocument) to allow for non-linear undo operations to be performed acrossthe dynamic regions in the document. In other words, the respectiveregion offset values for the dynamic regions can be used to resolve thedependency across the dynamic regions, thus enabling non-linear undoacross the dynamic regions in a document.

In an embodiment, the hybrid undo and redo capabilities may beimplemented and provided by a text editing application software.Nonlimiting examples of application software suitable for implementingthe techniques disclosed herein include VISUAL STUDIO CODE provided byMicrosoft Corporation of Redmond, Wash., Notepad++, or other suitabletext editing application software. The hybrid undo/redo is achieved bymaintaining respective region offset values for the dynamic regions inthe document.

For example, a user may edit (i.e., modify) a document using textediting software. At the start of the editing session, the document doesnot include any dynamic regions. The user may make a first edit to thetext in line 7 of the document, which causes the generation of a firstdynamic region that includes line 7 in the document. The first edit isrecorded as being made in (i.e., associated with) the first dynamicregion in the document. The user may then make a second edit to the textin line 13 of the document. Since line 13 is not sufficiently near thefirst dynamic region (e.g., line 13 is not within a threshold range ofthe first dynamic region), the second edit causes the generation of asecond dynamic region that includes line 13 in the document. As line 13is below line 7, the second dynamic region is located below (i.e., lowerthan) the first dynamic region in the document. The second edit isrecorded as being made in the second dynamic region. The user may thenmake a third edit that adds (inserts) a new line 9 in the document. Thethird edit also includes a change to original line 8 caused by acarriage return (e.g., line break) input to the end of original line 8to add new line 9. Since changed line 8 is sufficiently close to thefirst dynamic region, the first dynamic region is expanded to includelines 8 and 9 (i.e., the first dynamic region now includes lines 7-9),and the third edit is recorded as being made in the first dynamicregion. The addition of new line 9 causes the lines of text lower in thedocument (i.e., original lines 9 and higher) to shift down by one line.For instance, original line 9 before the addition of new line 9 becomesline 10 after the addition of new line 9, original line 10 before theaddition of new line 9 becomes line 11 after the addition of new line 9,and so on.

Since the second dynamic region, which includes original line 13, isbelow new line 9 in the document, original line 13 becomes line 14 afterthe addition of new line 9. To account for the shift downward oforiginal line 13 by one line, a region offset value associated with thesecond dynamic region is incremented by one (i.e., the value one isadded to the region offset value of the second dynamic region). Notethat, up to this point, the third edit is the last edit performed by theuser.

With linear undo, the user is able to undo the third edit but not thefirst or second edits. That is, the user is only able to undo the lastedit performed, and not able to undo the edits in an arbitrary order.

However, in accordance with the concepts, devices, systems, andtechniques described herein, by maintaining a region offset value forthe second dynamic region that accounts for the shift in the linesincluded in the second dynamic region, the user is able to undo the lastedit (i.e., in this example, the second edit) which was performed in thesecond dynamic region without first undoing the last edit (i.e., thethird edit) which was performed in the first dynamic region. In otherwords, the respective region offset values for the dynamic regions in adocument allow for performing undo operations in arbitrary order acrossthe dynamic regions in the document. This is because the region offsetvalue corresponds to a value that can be added to a base or relativeaddress to derive an actual address or location in the document at whichto perform the undo. These and other advantages, variations, andembodiments will be apparent in light of this disclosure.

Referring now to FIG. 1, shown is an illustrative network environment101 of computing devices in which various aspects of the disclosure maybe implemented, in accordance with an embodiment of the presentdisclosure. As shown, environment 101 includes one or more clientmachines 102A-102N, one or more remote machines 106A-106N, one or morenetworks 104, 104′, and one or more appliances 108 installed withinenvironment 101. Client machines 102A-102N communicate with remotemachines 106A-106N via networks 104, 104′.

In some embodiments, client machines 102A-102N communicate with remotemachines 106A-106N via an intermediary appliance 108. The illustratedappliance 108 is positioned between networks 104, 104′ and may also bereferred to as a network interface or gateway. In some embodiments,appliance 108 may operate as an application delivery controller (ADC) toprovide clients with access to business applications and other datadeployed in a datacenter, a cloud computing environment, or delivered asSoftware as a Service (SaaS) across a range of client devices, and/orprovide other functionality such as load balancing, etc. In someembodiments, multiple appliances 108 may be used, and appliance(s) 108may be deployed as part of network 104 and/or 104′.

Client machines 102A-102N may be generally referred to as clientmachines 102, local machines 102, clients 102, client nodes 102, clientcomputers 102, client devices 102, computing devices 102, endpoints 102,or endpoint nodes 102. Remote machines 106A-106N may be generallyreferred to as servers 106 or a server farm 106. In some embodiments, aclient device 102 may have the capacity to function as both a clientnode seeking access to resources provided by server 106 and as a server106 providing access to hosted resources for other client devices102A-102N. Networks 104, 104′ may be generally referred to as a network104. Networks 104 may be configured in any combination of wired andwireless networks.

Server 106 may be any server type such as, for example: a file server;an application server; a web server; a proxy server; an appliance; anetwork appliance; a gateway; an application gateway; a gateway server;a virtualization server; a deployment server; a Secure Sockets LayerVirtual Private Network (SSL VPN) server; a firewall; a web server; aserver executing an active directory; a cloud server; or a serverexecuting an application acceleration program that provides firewallfunctionality, application functionality, or load balancingfunctionality.

Server 106 may execute, operate or otherwise provide an application thatmay be any one of the following: software; a program; executableinstructions; a virtual machine; a hypervisor; a web browser; aweb-based client; a client-server application; a thin-client computingclient; an ActiveX control; a Java applet; software related to voiceover internet protocol (VoIP) communications like a soft IP telephone;an application for streaming video and/or audio; an application forfacilitating real-time-data communications; a HTTP client; a FTP client;an Oscar client; a Telnet client; or any other set of executableinstructions.

In some embodiments, server 106 may execute a remote presentationservices program or other program that uses a thin-client or aremote-display protocol to capture display output generated by anapplication executing on server 106 and transmit the application displayoutput to client device 102.

In yet other embodiments, server 106 may execute a virtual machineproviding, to a user of client device 102, access to a computingenvironment. Client device 102 may be a virtual machine. The virtualmachine may be managed by, for example, a hypervisor, a virtual machinemanager (VMM), or any other hardware virtualization technique withinserver 106.

In some embodiments, network 104 may be: a local-area network (LAN); ametropolitan area network (MAN); a wide area network (WAN); a primarypublic network; and a primary private network. Additional embodimentsmay include a network 104 of mobile telephone networks that use variousprotocols to communicate among mobile devices. For short rangecommunications within a wireless local-area network (WLAN), theprotocols may include 802.11, Bluetooth, and Near Field Communication(NFC).

FIG. 2 is a block diagram illustrating selective components of anillustrative computing device 100 in which various aspects of thedisclosure may be implemented, in accordance with an embodiment of thepresent disclosure. For instance, client devices 102, appliances 108,and/or servers 106 of FIG. 1 can be substantially similar to computingdevice 100. As shown, computing device 100 includes one or moreprocessors 103, a volatile memory 122 (e.g., random access memory(RAM)), a non-volatile memory 128, a user interface (UI) 123, one ormore communications interfaces 118, and a communications bus 150.

Non-volatile memory 128 may include: one or more hard disk drives (HDDs)or other magnetic or optical storage media; one or more solid statedrives (SSDs), such as a flash drive or other solid-state storage media;one or more hybrid magnetic and solid-state drives; and/or one or morevirtual storage volumes, such as a cloud storage, or a combination ofsuch physical storage volumes and virtual storage volumes or arraysthereof.

User interface 123 may include a graphical user interface (GUI) 124(e.g., a touchscreen, a display, etc.) and one or more input/output(I/O) devices 126 (e.g., a mouse, a keyboard, a microphone, one or morespeakers, one or more cameras, one or more biometric scanners, one ormore environmental sensors, and one or more accelerometers, etc.).

Non-volatile memory 128 stores an operating system 115, one or moreapplications 116, and data 117 such that, for example, computerinstructions of operating system 115 and/or applications 116 areexecuted by processor(s) 103 out of volatile memory 122. In someembodiments, volatile memory 122 may include one or more types of RAMand/or a cache memory that may offer a faster response time than a mainmemory. Data may be entered using an input device of GUI 124 or receivedfrom I/O device(s) 126. Various elements of computing device 100 maycommunicate via communications bus 150.

The illustrated computing device 100 is shown merely as an illustrativeclient device or server and may be implemented by any computing orprocessing environment with any type of machine or set of machines thatmay have suitable hardware and/or software capable of operating asdescribed herein.

Processor(s) 103 may be implemented by one or more programmableprocessors to execute one or more executable instructions, such as acomputer program, to perform the functions of the system. As usedherein, the term “processor” describes circuitry that performs afunction, an operation, or a sequence of operations. The function,operation, or sequence of operations may be hard coded into thecircuitry or soft coded by way of instructions held in a memory deviceand executed by the circuitry. A processor may perform the function,operation, or sequence of operations using digital values and/or usinganalog signals.

In some embodiments, the processor can be embodied in one or moreapplication specific integrated circuits (ASICs), microprocessors,digital signal processors (DSPs), graphics processing units (GPUs),microcontrollers, field programmable gate arrays (FPGAs), programmablelogic arrays (PLAs), multi-core processors, or general-purpose computerswith associated memory.

Processor 103 may be analog, digital or mixed signal. In someembodiments, processor 103 may be one or more physical processors, orone or more virtual (e.g., remotely located or cloud computingenvironment) processors. A processor including multiple processor coresand/or multiple processors may provide functionality for parallel,simultaneous execution of instructions or for parallel, simultaneousexecution of one instruction on more than one piece of data.

Communications interfaces 118 may include one or more interfaces toenable computing device 100 to access a computer network such as a LocalArea Network (LAN), a Wide Area Network (WAN), a Personal Area Network(PAN), or the Internet through a variety of wired and/or wirelessconnections, including cellular connections.

In described embodiments, computing device 100 may execute anapplication on behalf of a user of a client device. For example,computing device 100 may execute one or more virtual machines managed bya hypervisor. Each virtual machine may provide an execution sessionwithin which applications execute on behalf of a user or a clientdevice, such as a hosted desktop session. Computing device 100 may alsoexecute a terminal services session to provide a hosted desktopenvironment. Computing device 100 may provide access to a remotecomputing environment including one or more applications, one or moredesktop applications, and one or more desktop sessions in which one ormore applications may execute.

Referring to FIG. 3, a cloud computing environment 300 is depicted,which may also be referred to as a cloud environment, cloud computing orcloud network. Cloud computing environment 300 can provide the deliveryof shared computing services and/or resources to multiple users ortenants. For example, the shared resources and services can include, butare not limited to, networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, databases, software,hardware, analytics, and intelligence.

In cloud computing environment 300, one or more clients 102 a-102 n(such as those described above) are in communication with a cloudnetwork 304. Cloud network 304 may include back-end platforms, e.g.,servers, storage, server farms or data centers. The users or clients 102a-102 n can correspond to a single organization/tenant or multipleorganizations/tenants. More particularly, in one illustrativeimplementation, cloud computing environment 300 may provide a privatecloud serving a single organization (e.g., enterprise cloud). In anotherexample, cloud computing environment 300 may provide a community orpublic cloud serving multiple organizations/tenants.

In some embodiments, a gateway appliance(s) or service may be utilizedto provide access to cloud computing resources and virtual sessions. Byway of example, Citrix Gateway, provided by Citrix Systems, Inc., may bedeployed on-premises or on public clouds to provide users with secureaccess and single sign-on to virtual, SaaS and web applications.Furthermore, to protect users from web threats, a gateway such as CitrixSecure Web Gateway may be used. Citrix Secure Web Gateway uses acloud-based service and a local cache to check for URL reputation andcategory.

In still further embodiments, cloud computing environment 300 mayprovide a hybrid cloud that is a combination of a public cloud and aprivate cloud. Public clouds may include public servers that aremaintained by third parties to clients 102 a-102 n or theenterprise/tenant. The servers may be located off-site in remotegeographical locations or otherwise.

Cloud computing environment 300 can provide resource pooling to servemultiple users via clients 102 a-102 n through a multi-tenantenvironment or multi-tenant model with different physical and virtualresources dynamically assigned and reassigned responsive to differentdemands within the respective environment. The multi-tenant environmentcan include a system or architecture that can provide a single instanceof software, an application or a software application to serve multipleusers. In some embodiments, cloud computing environment 300 can provideon-demand self-service to unilaterally provision computing capabilities(e.g., server time, network storage) across a network for multipleclients 102 a-102 n. By way of example, provisioning services may beprovided through a system such as Citrix Provisioning Services (CitrixPVS). Citrix PVS is a software-streaming technology that deliverspatches, updates, and other configuration information to multiplevirtual desktop endpoints through a shared desktop image. Cloudcomputing environment 300 can provide an elasticity to dynamically scaleout or scale in response to different demands from one or more clients102. In some embodiments, cloud computing environment 300 can include orprovide monitoring services to monitor, control and/or generate reportscorresponding to the provided shared services and resources.

In some embodiments, cloud computing environment 300 may providecloud-based delivery of different types of cloud computing services,such as Software as a service (SaaS) 308, Platform as a Service (PaaS)312, Infrastructure as a Service (IaaS) 316, and Desktop as a Service(DaaS) 320, for example. IaaS may refer to a user renting the use ofinfrastructure resources that are needed during a specified time period.IaaS providers may offer storage, networking, servers or virtualizationresources from large pools, allowing the users to quickly scale up byaccessing more resources as needed. Examples of IaaS include AMAZON WEBSERVICES provided by Amazon.com, Inc., of Seattle, Wash., RACKSPACECLOUD provided by Rackspace US, Inc., of San Antonio, Tex., GoogleCompute Engine provided by Google Inc. of Mountain View, Calif., orRIGHTSCALE provided by RightScale, Inc., of Santa Barbara, Calif.

PaaS providers may offer functionality provided by IaaS, including,e.g., storage, networking, servers or virtualization, as well asadditional resources such as, e.g., the operating system, middleware, orruntime resources. Examples of PaaS include WINDOWS AZURE provided byMicrosoft Corporation of Redmond, Wash., Google App Engine provided byGoogle Inc., and HEROKU provided by Heroku, Inc. of San Francisco,Calif.

SaaS providers may offer the resources that PaaS provides, includingstorage, networking, servers, virtualization, operating system,middleware, or runtime resources. In some embodiments, SaaS providersmay offer additional resources including, e.g., data and applicationresources. Examples of SaaS include GOOGLE APPS provided by Google Inc.,SALESFORCE provided by Salesforce.com Inc. of San Francisco, Calif., orOFFICE 365 provided by Microsoft Corporation. Examples of SaaS may alsoinclude data storage providers, e.g. Citrix ShareFile from CitrixSystems, DROPBOX provided by Dropbox, Inc. of San Francisco, Calif.,Microsoft SKYDRIVE provided by Microsoft Corporation, Google Driveprovided by Google Inc., or Apple ICLOUD provided by Apple Inc. ofCupertino, Calif. For example, in some embodiments, the hybrid undo/redoconcepts and techniques described herein can be implemented by a SaaSapplication to support text processing with region based undo/redofunctionality via the RESTful application programming interface (API) orlibrary.

Similar to SaaS, DaaS (which is also known as hosted desktop services)is a form of virtual desktop infrastructure (VDI) in which virtualdesktop sessions are typically delivered as a cloud service along withthe apps used on the virtual desktop. Citrix Cloud from Citrix Systemsis one example of a DaaS delivery platform. DaaS delivery platforms maybe hosted on a public cloud computing infrastructure such as AZURE CLOUDfrom Microsoft Corporation of Redmond, Wash. (herein “Azure”), or AMAZONWEB SERVICES provided by Amazon.com, Inc., of Seattle, Wash. (herein“AWS”), for example. In the case of Citrix Cloud, Citrix Workspace appmay be used as a single-entry point for bringing apps, files anddesktops together (whether on-premises or in the cloud) to deliver aunified experience.

FIG. 4A is a block diagram of an illustrative system 400 in which one ormore resource management services 402 may manage and streamline accessby one or more clients 202 to one or more resource feeds 406 (via one ormore gateway services 408) and/or one or more software-as-a-service(SaaS) applications 410. In particular, resource management service(s)402 may employ an identity provider 412 to authenticate the identity ofa user of a client 202 and, following authentication, identify one ofmore resources the user is authorized to access. In response to the userselecting one of the identified resources, resource managementservice(s) 402 may send appropriate access credentials to the requestingclient 202, and the requesting client 202 may then use those credentialsto access the selected resource. For resource feed(s) 406, client 202may use the supplied credentials to access the selected resource viagateway service 408. For SaaS application(s) 410, client 202 may use thecredentials to access the selected application directly.

Client(s) 202 may be any type of computing devices capable of accessingresource feed(s) 406 and/or SaaS application(s) 410, and may, forexample, include a variety of desktop or laptop computers, smartphones,tablets, etc. Resource feed(s) 406 may include any of numerous resourcetypes and may be provided from any of numerous locations. In someembodiments, for example, resource feed(s) 406 may include one or moresystems or services for providing virtual applications and/or desktopsto client(s) 202, one or more file repositories and/or file sharingsystems, one or more secure browser services, one or more access controlservices for SaaS applications 410, one or more management services forlocal applications on client(s) 202, one or more internet enableddevices or sensors, etc. Each of resource management service(s) 402,resource feed(s) 406, gateway service(s) 408, SaaS application(s) 410,and identity provider 412 may be located within an on-premises datacenter of an organization for which system 400 is deployed, within oneor more cloud computing environments, or elsewhere.

FIG. 4B is a block diagram showing an illustrative implementation ofsystem 400 shown in FIG. 4A in which various resource managementservices 402 as well as gateway service 408 are located within a cloudcomputing environment 414. The cloud computing environment may, forexample, include Microsoft Azure Cloud, Amazon Web Services, GoogleCloud, or IBM Cloud.

For any of illustrated components (other than client 202) that are notbased within cloud computing environment 414, cloud connectors (notshown in FIG. 4B) may be used to interface those components with cloudcomputing environment 414. Such cloud connectors may, for example, runon Windows Server instances hosted in resource locations and may createa reverse proxy to route traffic between the site(s) and cloud computingenvironment 414. In the illustrated example, the cloud-based resourcemanagement services 402 include a client interface service 416, anidentity service 418, a resource feed service 420, and a single sign-onservice 422. As shown, in some embodiments, client 202 may use aresource access application 424 to communicate with client interfaceservice 416 as well as to present a user interface on client 202 that auser 426 can operate to access resource feed(s) 406 and/or SaaSapplication(s) 410. Resource access application 424 may either beinstalled on client 202 or may be executed by client interface service416 (or elsewhere in system 400) and accessed using a web browser (notshown in FIG. 4B) on client 202. For instance, in the case of CitrixCloud, in some embodiments, resource access application 424 may beCitrix Workspace App and be programmed or otherwise configured toprovide text processing with region based undo/redo. Text processingwith region based undo/redo will be further described below at least inconjunction with FIGS. 5-17.

As explained in more detail below, in some embodiments, resource accessapplication 424 and associated components may provide user 426 with apersonalized, all-in-one interface enabling instant and seamless accessto all the user's SaaS and web applications, files, virtual Windowsapplications, virtual Linux applications, desktops, mobile applications,Citrix Virtual Apps and Desktops™, local applications, and other data.

When resource access application 424 is launched or otherwise accessedby user 426, client interface service 416 may send a sign-on request toidentity service 418. In some embodiments, identity provider 412 may belocated on the premises of the organization for which system 400 isdeployed. Identity provider 412 may, for example, correspond to anon-premises Windows Active Directory. In such embodiments, identityprovider 412 may be connected to the cloud-based identity service 418using a cloud connector (not shown in FIG. 4B), as described above. Uponreceiving a sign-on request, identity service 418 may cause resourceaccess application 424 (via client interface service 416) to prompt user426 for the user's authentication credentials (e.g., username andpassword). Upon receiving the user's authentication credentials, clientinterface service 416 may pass the credentials along to identity service418, and identity service 418 may, in turn, forward them to identityprovider 412 for authentication, for example, by comparing them againstan Active Directory domain. Once identity service 418 receivesconfirmation from identity provider 412 that the user's identity hasbeen properly authenticated, client interface service 416 may send arequest to resource feed service 420 for a list of subscribed resourcesfor user 426.

In other embodiments (not illustrated in FIG. 4B), identity provider 412may be a cloud-based identity service, such as a Microsoft Azure ActiveDirectory. In such embodiments, upon receiving a sign-on request fromclient interface service 416, identity service 418 may, via clientinterface service 416, cause client 202 to be redirected to thecloud-based identity service to complete an authentication process. Thecloud-based identity service may then cause client 202 to prompt user426 to enter the user's authentication credentials. Upon determining theuser's identity has been properly authenticated, the cloud-basedidentity service may send a message to resource access application 424indicating the authentication attempt was successful, and resourceaccess application 424 may then inform client interface service 416 ofthe successfully authentication. Once identity service 418 receivesconfirmation from client interface service 416 that the user's identityhas been properly authenticated, client interface service 416 may send arequest to resource feed service 420 for a list of subscribed resourcesfor user 426.

For each configured resource feed, resource feed service 420 may requestan identity token from single sign-on service 422. Resource feed service420 may then pass the feed-specific identity tokens it receives to thepoints of authentication for the respective resource feeds 406. Eachresource feed 406 may then respond with a list of resources configuredfor the respective identity. Resource feed service 420 may thenaggregate all items from the different feeds and forward them to clientinterface service 416, which may cause resource access application 424to present a list of available resources on a user interface of client202. The list of available resources may, for example, be presented onthe user interface of client 202 as a set of selectable icons or otherelements corresponding to accessible resources. The resources soidentified may, for example, include one or more virtual applicationsand/or desktops (e.g., Citrix Virtual Apps and Desktops™, VMwareHorizon, Microsoft RDS, etc.), one or more file repositories and/or filesharing systems (e.g., Sharefile®, one or more secure browsers, one ormore internet enabled devices or sensors, one or more local applicationsinstalled on client 202, and/or one or more SaaS applications 410 towhich user 426 has subscribed. The lists of local applications and SaaSapplications 410 may, for example, be supplied by resource feeds 406 forrespective services that manage which such applications are to be madeavailable to user 426 via resource access application 424. Examples ofSaaS applications 410 that may be managed and accessed as describedherein include Microsoft Office 365 applications, SAP SaaS applications,Workday applications, etc.

For resources other than local applications and SaaS application(s) 410,upon user 426 selecting one of the listed available resources, resourceaccess application 424 may cause client interface service 416 to forwarda request for the specified resource to resource feed service 420. Inresponse to receiving such a request, resource feed service 420 mayrequest an identity token for the corresponding feed from single sign-onservice 422. Resource feed service 420 may then pass the identity tokenreceived from single sign-on service 422 to client interface service 416where a launch ticket for the resource may be generated and sent toresource access application 424. Upon receiving the launch ticket,resource access application 424 may initiate a secure session to gatewayservice 408 and present the launch ticket. When gateway service 408 ispresented with the launch ticket, it may initiate a secure session tothe appropriate resource feed and present the identity token to thatfeed to seamlessly authenticate user 426. Once the session initializes,client 202 may proceed to access the selected resource.

When user 426 selects a local application, resource access application424 may cause the selected local application to launch on client 202.When user 426 selects SaaS application 410, resource access application424 may cause client interface service 416 request a one-time uniformresource locator (URL) from gateway service 408 as well a preferredbrowser for use in accessing SaaS application 410. After gateway service408 returns the one-time URL and identifies the preferred browser,client interface service 416 may pass that information along to resourceaccess application 424. Client 202 may then launch the identifiedbrowser and initiate a connection to gateway service 408. Gatewayservice 408 may then request an assertion from single sign-on service422. Upon receiving the assertion, gateway service 408 may cause theidentified browser on client 202 to be redirected to the logon page foridentified SaaS application 410 and present the assertion. The SaaS maythen contact gateway service 408 to validate the assertion andauthenticate user 426. Once the user has been authenticated,communication may occur directly between the identified browser and theselected SaaS application 410, thus allowing user 426 to use client 202to access the selected SaaS application 410.

In some embodiments, the preferred browser identified by gateway service408 may be a specialized browser embedded in resource access application424 (when the resource application is installed on client 202) orprovided by one of the resource feeds 406 (when resource application 424is located remotely), e.g., via a secure browser service. In suchembodiments, SaaS applications 410 may incorporate enhanced securitypolicies to enforce one or more restrictions on the embedded browser.Examples of such policies include (1) requiring use of the specializedbrowser and disabling use of other local browsers, (2) restrictingclipboard access, e.g., by disabling cut/copy/paste operations betweenthe application and the clipboard, (3) restricting printing, e.g., bydisabling the ability to print from within the browser, (3) restrictingnavigation, e.g., by disabling the next and/or back browser buttons, (4)restricting downloads, e.g., by disabling the ability to download fromwithin the SaaS application, and (5) displaying watermarks, e.g., byoverlaying a screen-based watermark showing the username and IP addressassociated with client 202 such that the watermark will appear asdisplayed on the screen if the user tries to print or take a screenshot.Further, in some embodiments, when a user selects a hyperlink within aSaaS application, the specialized browser may send the URL for the linkto an access control service (e.g., implemented as one of the resourcefeed(s) 406) for assessment of its security risk by a web filteringservice. For approved URLs, the specialized browser may be permitted toaccess the link. For suspicious links, however, the web filteringservice may have client interface service 416 send the link to a securebrowser service, which may start a new virtual browser session withclient 202, and thus allow the user to access the potentially harmfullinked content in a safe environment.

In some embodiments, in addition to or in lieu of providing user 426with a list of resources that are available to be accessed individually,as described above, user 426 may instead be permitted to choose toaccess a streamlined feed of event notifications and/or availableactions that may be taken with respect to events that are automaticallydetected with respect to one or more of the resources. This streamlinedresource activity feed, which may be customized for each user 426, mayallow users to monitor important activity involving all of theirresources—SaaS applications, web applications, Windows applications,Linux applications, desktops, file repositories and/or file sharingsystems, and other data through a single interface, without needing toswitch context from one resource to another. Further, eventnotifications in a resource activity feed may be accompanied by adiscrete set of user-interface elements, e.g., “approve,” “deny,” and“see more detail” buttons, allowing a user to take one or more simpleactions with respect to each event right within the user's feed. In someembodiments, such a streamlined, intelligent resource activity feed maybe enabled by one or more micro-applications, or “microapps,” that caninterface with underlying associated resources using APIs or the like.The responsive actions may be user-initiated activities that are takenwithin the microapps and that provide inputs to the underlyingapplications through the API or other interface. The actions a userperforms within the microapp may, for example, be designed to addressspecific common problems and use cases quickly and easily, adding toincreased user productivity (e.g., request personal time off, submit ahelp desk ticket, etc.). In some embodiments, notifications from suchevent-driven microapps may additionally or alternatively be pushed toclients 202 to notify user 426 of something that requires the user'sattention (e.g., approval of an expense report, new course available forregistration, etc.).

FIG. 4C is a block diagram similar to that shown in FIG. 4B but in whichthe available resources (e.g., SaaS applications, web applications,Windows applications, Linux applications, desktops, file repositoriesand/or file sharing systems, and other data) are represented by a singlebox 428 labeled “systems of record,” and further in which severaldifferent services are included within the resource management servicesblock 402. As explained below, the services shown in FIG. 4C may enablethe provision of a streamlined resource activity feed and/ornotification process for client 202. In the example shown, in additionto client interface service 416 discussed above, the illustratedservices include a microapp service 430, a data integration providerservice 432, a credential wallet service 434, an active data cacheservice 436, an analytics service 438, and a notification service 440.In various embodiments, the services shown in FIG. 4C may be employedeither in addition to or instead of the different services shown in FIG.4B.

In some embodiments, a microapp may be a single use case made availableto users to streamline functionality from complex enterpriseapplications. Microapps may, for example, utilize APIs available withinSaaS, web, or home-grown applications allowing users to see contentwithout needing a full launch of the application or the need to switchcontext. Absent such microapps, users would need to launch anapplication, navigate to the action they need to perform, and thenperform the action. Microapps may streamline routine tasks forfrequently performed actions and provide users the ability to performactions within resource access application 424 without having to launchthe native application. The system shown in FIG. 4C may, for example,aggregate relevant notifications, tasks, and insights, and thereby giveuser 426 a dynamic productivity tool. In some embodiments, the resourceactivity feed may be intelligently populated by utilizing machinelearning and artificial intelligence (AI) algorithms. Further, in someimplementations, microapps may be configured within cloud computingenvironment 414, thus giving administrators a powerful tool to createmore productive workflows, without the need for additionalinfrastructure. Whether pushed to a user or initiated by a user,microapps may provide short cuts that simplify and streamline key tasksthat would otherwise require opening full enterprise applications. Insome embodiments, out-of-the-box templates may allow administrators withAPI account permissions to build microapp solutions targeted for theirneeds. Administrators may also, in some embodiments, be provided withthe tools they need to build custom microapps.

Referring to FIG. 4C, systems of record 428 may represent theapplications and/or other resources resource management services 402 mayinteract with to create microapps. These resources may be SaaSapplications, legacy applications, or homegrown applications, and can behosted on-premises or within a cloud computing environment. Connectorswith out-of-the-box templates for several applications may be providedand integration with other applications may additionally oralternatively be configured through a microapp page builder. Such amicroapp page builder may, for example, connect to legacy, on-premises,and SaaS systems by creating streamlined user workflows via microappactions. Resource management services 402, and in particular dataintegration provider service 432, may, for example, support REST API,JSON, OData-JSON, and 6ML. As explained in more detail below, dataintegration provider service 432 may also write back to the systems ofrecord, for example, using OAuth2 or a service account.

In some embodiments, microapp service 430 may be a single-tenant serviceresponsible for creating the microapps. Microapp service 430 may sendraw events, pulled from systems of record 428, to analytics service 438for processing. The microapp service may, for example, periodically pullactive data from systems of record 428.

In some embodiments, active data cache service 436 may be single-tenantand may store all configuration information and microapp data. It may,for example, utilize a per-tenant database encryption key and per-tenantdatabase credentials.

In some embodiments, credential wallet service 434 may store encryptedservice credentials for systems of record 428 and user OAuth2 tokens.

In some embodiments, data integration provider service 432 may interactwith systems of record 428 to decrypt end-user credentials and writeback actions to systems of record 428 under the identity of theend-user. The write-back actions may, for example, utilize a user'sactual account to ensure all actions performed are compliant with datapolicies of the application or other resource being interacted with.

In some embodiments, analytics service 438 may process the raw eventsreceived from microapps service 430 to create targeted scorednotifications and send such notifications to notification service 440.

Finally, in some embodiments, notification service 440 may process anynotifications it receives from analytics service 438. In someimplementations, notification service 440 may store the notifications ina database to be later served in a notification feed. In otherembodiments, notification service 440 may additionally or alternativelysend the notifications out immediately to client 202 as a pushnotification to user 426.

In some embodiments, a process for synchronizing with systems of record428 and generating notifications may operate as follows. Microappservice 430 may retrieve encrypted service account credentials forsystems of record 428 from credential wallet service 434 and request async with data integration provider service 432. Data integrationprovider service 432 may then decrypt the service account credentialsand use those credentials to retrieve data from systems of record 428.Data integration provider service 432 may then stream the retrieved datato microapp service 430. Microapp service 430 may store the receivedsystems of record data in active data cache service 436 and also sendraw events to analytics service 438. Analytics service 438 may createtargeted scored notifications and send such notifications tonotification service 440. Notification service 440 may store thenotifications in a database to be later served in a notification feedand/or may send the notifications out immediately to client 202 as apush notification to user 426.

In some embodiments, a process for processing a user-initiated actionvia a microapp may operate as follows. Client 202 may receive data frommicroapp service 430 (via client interface service 416) to renderinformation corresponding to the microapp. Microapp service 430 mayreceive data from active data cache service 436 to support thatrendering. User 426 may invoke an action from the microapp, causingresource access application 424 to send that action to microapp service430 (via client interface service 416). Microapp service 430 may thenretrieve from credential wallet service 434 an encrypted Oauth2 tokenfor the system of record for which the action is to be invoked and maysend the action to data integration provider service 432 together withthe encrypted Oath2 token. Data integration provider service 432 maythen decrypt the Oath2 token and write the action to the appropriatesystem of record under the identity of user 426. Data integrationprovider service 432 may then read back changed data from the written-tosystem of record and send that changed data to microapp service 430.Microapp service 432 may then update active data cache service 436 withthe updated data and cause a message to be sent to resource accessapplication 424 (via client interface service 416) notifying user 426that the action was successfully completed.

In some embodiments, in addition to or in lieu of the functionalitydescribed above, resource management services 402 may provide users theability to search for relevant information across all files andapplications. A simple keyword search may, for example, be used to findapplication resources, SaaS applications, desktops, files, etc. Thisfunctionality may enhance user productivity and efficiency asapplication and data sprawl is prevalent across all organizations.

In other embodiments, in addition to or in lieu of the functionalitydescribed above, resource management services 402 may enable virtualassistance functionality that allows users to remain productive and takequick actions. Users may, for example, interact with the “VirtualAssistant” and ask questions such as “What is Bob Smith's phone number?”or “What absences are pending my approval?” Resource management services402 may, for example, parse these requests and respond because they areintegrated with multiple systems on the backend. In some embodiments,users may be able to interact with the virtual assistance through eitherresource access application 424 or directly from another resource, suchas Microsoft Teams. This feature may allow employees to workefficiently, stay organized, and deliver only the specific informationthey're looking for.

FIG. 5 is a block diagram showing example dynamic regions 506, 508, 510in a document 504, in accordance with an embodiment of the presentdisclosure. For example, as shown in FIG. 5, a user may be editingdocument 504 using a text editing application 502 running on a suitablecomputing device, such as computing device 400 of FIG. 4. In response tothe user's edits to document 504, as shown in FIG. 5, application 502may create dynamic region A 506, dynamic region B 508, and dynamicregion C 510. Dynamic regions 506, 508, 510 define respective regions indocument 504 where one or more edits have been made to the document. Ingeneral, dynamic regions 506, 508, 510 are “dynamic” in the sense that,once created, the regions may adjust or otherwise change in size and/orlocation within the document based on additional edits made to thedocument. For instance, dynamic region A 506 defines a region indocument 504 that includes or hosts one or more edits made by the user,dynamic region B 508 defines a region in document 504 that includes orhosts one or more edits made by the user, and dynamic region C 510defines a region in document 504 that includes or hosts one or moreedits made by the user. To this end, dynamic regions 506, 508, 510 maybe defined using respective dynamic region start values and dynamicregion end values. A dynamic region start value indicates a line numberin document 504 at which a particular dynamic region starts, and adynamic region end value indicates a line number in document 504 atwhich the particular dynamic region ends. Also, as further shown in FIG.5, within document 504, dynamic region A 506 is located above dynamicregion B 508 which is located above dynamic region C 510. While onlythree dynamic regions are depicted in FIG. 5 for purposes of clarity, itwill be appreciated that application 502 may create any number ofdynamic regions in document 504 based on the locations of the edits madeby the user in document 504.

Still referring to FIG. 5, dynamic regions 506, 508, 510 have undostacks and redo stacks. For instance, as shown, dynamic region A 506 hasan undo stack 506 a and a redo stack 506 b, dynamic region B 508 has anundo stack 508 a and a redo stack 508 b, and dynamic region C 510 has anundo stack 510 a and a redo stack 510 b. Undo stacks 506 a, 508 a, 510 aand redo stacks 506 b, 508 b, 510 b may be implemented as last in firstout (LIFO) data structures that store the edit operations and the undooperations, respectively, performed to document 504. For instance, whenan edit operation is performed in dynamic region A 506, the edit actionis pushed onto the top of undo stack 506 a. Similarly, when an editoperation is performed in dynamic region B 508, the edit action ispushed onto the top of undo stack 508 a, and when an edit operation isperformed in dynamic region C 510, the edit action is pushed onto thetop of undo stack 510 a.

When the user triggers an undo action in a dynamic region, the editaction at the top of the undo stack for the dynamic region is popped(i.e., removed from the top of the undo stack), the inverse of thepopped edit action performed, and the edit action popped from the undostack is pushed (i.e., placed) onto the top of the redo stack of thedynamic region. Note that the inverse of the popped edit action isperformed in order to undo the edit action. Also, pushing the editaction that was popped from the undo stack onto the top of the redostack allows for redoing the undone edit action at a later time. Forinstance, when an undo action is triggered in dynamic region A 506, theedit action at the top of undo stack 506 a is popped, the inverse of thepopped edit action performed, and the edit action popped from undo stack506 a pushed onto the top of redo stack 506 b. Similarly, when an undoaction is triggered in dynamic region B 508, the edit action at the topof undo stack 508 a is popped, the inverse of the popped edit actionperformed, and the edit action popped from undo stack 508 a pushed ontothe top of redo stack 508 b, and when an undo action is triggered indynamic region C 510, the edit action at the top of undo stack 510 a ispopped, the inverse of the popped edit action performed, and the editaction popped from undo stack 510 a pushed onto the top of redo stack510 b.

When the user triggers a redo action in a dynamic region, the editaction at the top of the redo stack of the dynamic region is popped, thepopped edit action performed, and the edit action popped from the redostack (i.e., the performed redo action) is pushed onto the top of theundo of the dynamic region. For instance, when a redo action istriggered in dynamic region A 506, the edit action at the top of redostack 506 b is popped, the popped edit action performed, and theperformed edit action pushed onto the top of undo stack 506 a.Similarly, when a redo action is triggered in dynamic region B 508, theedit action at the top of redo stack 508 b is popped, the popped editaction performed, and the performed edit action pushed onto the top ofundo stack 508 a, and when a redo action is triggered in dynamic regionC 510, the edit action at the top of redo stack 510 b is popped, thepopped edit action performed, and the performed edit action pushed ontothe top of undo stack 510 a. The result of generating distinct dynamicregions in a document and maintaining respective undo and redo stacksfor the distinct dynamic regions, is the ability to perform non-linearundo operations across the dynamic regions from the perspective of alledits made to the document. However, within a dynamic region, the undoand redo operations are linear since one undo stack and one redo stackare used to store the edits made within the dynamic region.

FIG. 6 is a diagram of an example dynamic region data structure 600, inaccordance with an embodiment of the present disclosure. In anembodiment, text editing application 502 may generate and maintainrespective dynamic region data structures 600 for the dynamic regionscreated in a document. For example, in an implementation, text editingapplication 502 may create a dynamic region in a document the first timea user changes a line or consecutive lines in the document. Text editingapplication 502 may delete (i.e., remove) a dynamic region created in adocument upon the user undoing all the changes made in the dynamicregion. Text editing application 502 may merge (i.e., join) neighboringor adjacent dynamic regions in the document into a single dynamic regionif the user makes a change across neighboring dynamic regions. Textediting application 502 may separate a dynamic region in the documentinto two neighboring dynamic regions if the user undoes a change thatcaused the merging of the two neighboring dynamic regions.

As shown in FIG. 6, dynamic region data structure 600 includes a regionstart value, a region end value, and a region offset value. The regionstart value indicates a relative start line number for a dynamic regiondefined by dynamic region data structure 600. The region end valueindicates a relative end line number for the dynamic region defined bydynamic region data structure 600. The region offset value indicates aline number offset inside of the dynamic region defined by dynamicregion data structure 600. The region offset value may be a positivevalue (i.e., offset of a positive number of lines) or a negative value(i.e., offset of a negative number of lines). An edit dependency issuemay arise in instances where lines are added or deleted in a particulardynamic region, and the line numbers in the document below thisparticular dynamic region are impacted by the number of lines added ordeleted in the particular dynamic region. In these cases, thecorresponding line numbers in dynamic regions below the particulardynamic region will need to be adjusted to account for the number oflines added or deleted in the particular dynamic region. That is, theline numbers may change based upon the addition or deletion being made.Thus, the line numbers are said to be dependent upon the edits beingmade. To this end, respective region offset values of the dynamicregions below the particular dynamic region are updated to account forthe added or deleted lines in the particular dynamic region. Thus, theregion offset value is used to resolve the edit dependency issue acrossthe dynamic regions created in the document.

The region start and the region end values may be relative values inthat these values may not indicate actual (i.e., real) start line numberand end line number of the dynamic region in the document. In otherwords, the region start value and the region end value may not indicatethe actual location of the dynamic region in the document at a givenpoint in time during the editing session. Rather, the actual start linenumber of the dynamic region in the document can be computed orotherwise determined as the sum of the region start value and the regionoffset value (region start value+region offset value). Similarly, theactual end line number of the dynamic region in the document can becomputed or otherwise determined as the sum of the region end value andthe region offset value (region end value+region offset value). Forexample, suppose a dynamic region in a document is defined by a regionstart value of 8, a region end value of 10, and a region offset valueof 1. In this case, the actual start line number of the dynamic regionin the document is line 9 (8+1) and the actual end line number of thedynamic region is line 11 (10+1). In the example above, suppose theregion offset value is −2. In this case, the actual start line number ofthe dynamic region in the document is line 6 (8−2) and the actual endline number of the dynamic region is line eight 8 (10−2).

FIG. 7 is a diagram of an example edit operation record 700, inaccordance with an embodiment of the present disclosure. In anembodiment, text editing application 502 may generate and maintainrespective edit operation records 700 for the edit operations performedduring a document editing session. As shown, edit operation record 700includes a description of an edit operation, a line start value, a lineend value, and an optional change number value. The description of anedit operation defines or otherwise describes the edit or change that ismade to the document by the edit operation. The line start valueindicates a start line number in the document that was changed (i.e.,affected) by the edit operation. The line end value indicates an endline number in the document that was changed by the edit operation. Inother words, the line start value indicates a location (i.e., linenumber) in the document at which the edit operation starts, and the lineend value indicates a location (i.e., line number) in the document atwhich the edit operation ends. For example, if an edit operation changeslines 7 and 8 in a document, the line start value may be set 7 and theline end value may be set to 8. The optional change number value is avalue that uniquely identifies the edit operation in the editingsession. For example, if the edit operation is the seventh editingoperation performed during the editing session, the change number valuemay be set to 7.

FIGS. 8A-8E show an example operation of dynamic region data structuresin processing edit operations performed during a document editingsession, in accordance with an embodiment of the present disclosure.Text editing application 502 may use dynamic region data structures tomanage the generation and manipulation of dynamic regions during adocument editing session. In an example use case and embodiment, a usermay access and edit the contents of a document using text editingapplication 502. At the start of a document editing session by the user,text editing application 502 initializes or starts without any dynamicregions in the document.

For example, at the start of the editing session, the user may make anedit to the text in line 1 of the document. In response to detecting theedit to line 1, text editing application 502 (FIG. 5) may create an editoperation record 810 to record the change to the document resulting fromthe edit to line 1. To this end, as can be seen in FIG. 8A, text editingapplication 502 may include in edit operation record 810 a descriptionof the change to line 1 (denoted C1 in FIG. 8A), and set the line startvalue to line 1 (LS: 1) and the line end value to line 1 (LE: 1). Sincethe resulting change is to a single line (line 1), the line start valueis the same as the line end value.

In an implementation, text editing application 502 may store editoperation record 810 in an optional global change stack 802. Textediting application 502 may use global change stack 802 to record ahistory of the edit operations executed during the editing session. Tothis end, when a new edit operation is executed, text editingapplication 502 may add an edit operation record corresponding to thenew edit operation to the top of global change stack 802.

Text editing application 502 may also check to determine whether theedit operation (i.e., change to line 1) is or otherwise occurs in anexisting dynamic region or within a threshold range of an existingdynamic region in the document. In an embodiment, the threshold rangefor a dynamic region may be defined by the following:

[region start value+region offset value−1, region end value+regionoffset value+1]

The threshold range specifies a number of lines from the actual start ofthe dynamic region and a number of lines from the actual end of thedynamic region in the document. For instance, according to the rangespecified above, the threshold range for a dynamic region is one linebefore the actual start of the dynamic region (region start value+regionoffset value−1) to one line following the actual end of the dynamicregion (region end value+region offset value+1) in the document. If theedit is within the threshold range of a dynamic region, text editingapplication 502 processes the edit as if the edit results in a changewithin the dynamic region. In other embodiments, the threshold range maybe a different number of lines, such as two, three, or any othersuitable value, from the actual start and actual end of a dynamicregion. Moreover, the threshold range may specify different number oflines from the actual start of a dynamic region and the actual end ofthe dynamic region. For example, a threshold range may specify one linefrom the actual start of a dynamic region and two lines from the actualend of the dynamic region.

At this point, since no dynamic regions have been created in thedocument, text editing application 502 may create a dynamic region A forthis edit operation (i.e., change to line 1). To this end, as can beseen in FIG. 8A, text editing application 502 may create a dynamicregion A data structure 804A, a dynamic region A undo stack 806A, and adynamic region A redo stack 808A.

Dynamic region A data structure 804A defines dynamic region A created tohost the edit to line 1. Accordingly, text editing application 502 mayset the region start value to line 1 (RS: 1), the region end value toline 1 (RE: 1), and the region offset value to zero (Off: 0). In otherwords, at this point, dynamic region A includes only line 1. Textediting application 502 may push edit operation record 810 onto the topof dynamic region A undo stack 806A. As the last executed edit operationin dynamic region A, the edit operation (i.e., the change to line 1 asrecorded in edit operation record 810) can be popped from the top ofdynamic region A undo stack 806A and undone.

Continuing the example use case, the user may then make an edit to thetext in line 7 of the document. In response to detecting the edit toline 7, text editing application 502 may create an edit operation record812 to record the change to the document resulting from the edit to line7. To this end, as can be seen in FIG. 8B, text editing application 502may include in edit operation record 812 a description of the change toline 7 (denoted C2 in FIG. 8B), and set the line start value to line 7(LS: 7) and the line end value to line 7 (LE: 7). Since the resultingchange is to a single line (line 7), the line start value is the same asthe line end value.

Text editing application 502 may check to determine whether the editoperation (i.e., change to line 7) is or otherwise occurs in an existingdynamic region or within a threshold range of an existing dynamic regionin the document. At this point, the document includes dynamic region Aas defined by dynamic region A data structure 804A. Text editingapplication 502 may determine that the changed line 7 is not in orwithin the threshold range of dynamic region A. As a result of thisdetermination, text editing application 502 may create a dynamic regionB for this edit operation (i.e., change to line 7). To this end, as canbe seen in FIG. 8B, text editing application 502 may create a dynamicregion B data structure 804B, a dynamic region B undo stack 806B, and adynamic region B redo stack 808B. Dynamic region B data structure 804Bdefines dynamic region B created to host the edit to line 7.Accordingly, text editing application 502 may set the region start valueto line 7 (RS: 7), the region end value to line 7 (RE: 7), and theregion offset value to zero (Off: 0). In other words, at this point,dynamic region B includes only line 7. Text editing application 502 maypush edit operation record 812 onto the top of dynamic region B undostack 806B. As the last executed edit operation in dynamic region B, theedit operation (i.e., the change to line 7 as recorded in edit operationrecord 812) can be popped from the top of dynamic region B undo stack806B and undone.

Note that since dynamic region A has its own dynamic region A undo stack806A, the edit to line 1 recorded by edit operation record 810 can bepopped from the top of dynamic region A undo stack 806A and undonewithout having to first undo the edit to line 7. Simply stated, sincedynamic region A and dynamic region B have their own undo stack, thelast edit operation performed in dynamic region A (change to line 1) canbe undone even though the edit operation performed in dynamic region B(change to line 7) happens to be the last edit operation performed inthe document. The result is the non-linear nature of undo operationsacross the dynamic regions in the document.

Continuing the example use case, the user may then make an edit to thetext in line 20 of the document. In response to detecting the edit toline 20, text editing application 502 may create an edit operationrecord 814 to record the change to the document resulting from the editto line 20. To this end, as can be seen in FIG. 8C, text editingapplication 502 may include in edit operation record 814 a descriptionof the change to line 20 (denoted C3 in FIG. 8C), and set the line startvalue to line 20 (LS: 20) and the line end value to line 20 (LE: 20).Since the resulting change is to a single line (line 20), the line startvalue is the same as the line end value.

Text editing application 502 may check to determine whether the editoperation (i.e., change to line 20) is or otherwise occurs in anexisting dynamic region or within a threshold range of an existingdynamic region in the document. At this point, the document includesdynamic region A as defined by dynamic region A data structure 804A anddynamic region B as defined by dynamic region B data structure 804B.Text editing application 502 may determine that the changed line 20 isnot in or within the threshold range of either dynamic region A ordynamic region B. As a result of this determination, text editingapplication 502 may create a dynamic region C for this edit operation(i.e., change to line 20).

To this end, as can be seen in FIG. 8C, text editing application 502 maycreate a dynamic region C data structure 804C, a dynamic region C undostack 806C, and a dynamic region C redo stack 808C. Dynamic region Cdata structure 804C defines dynamic region C created to host the edit toline 20. Accordingly, text editing application 502 may set the regionstart value to line 20 (RS: 20), the region end value to line 20 (RE:20), and the region offset value to zero (Off: 0). In other words, atthis point, dynamic region C includes only line 20. Text editingapplication 502 may push edit operation record 814 onto the top ofdynamic region C undo stack 806C. As the last executed edit operation indynamic region C, the edit operation (i.e., the change to line 20 asrecorded in edit operation record 814) can be popped from the top ofdynamic region C undo stack 806C and undone.

Note that since dynamic region A has its own dynamic region A undo stack806A, the edit to line 1 recorded by edit operation record 810 can bepopped from the top of dynamic region A undo stack 806A and undonewithout having to first undo the edit to line 20. Similarly, sincedynamic region B has its own dynamic region B undo stack 806B, the editto line 7 recorded by edit operation record 812 can be popped from thetop of dynamic region B undo stack 806B and undone without having tofirst undo the edit to line 20. Simply stated, since dynamic region A,dynamic region B, and dynamic region C each have their own undo stack,the last edit operation performed in dynamic region A (change to line 1)and/or in dynamic region B (change to line 7) can be undone even thoughthe edit operation performed in dynamic region C (change to line 20)happens to be the last edit operation performed in the document.

Continuing the example use case, the user may then make an edit to add anew line 3 in the document. For instance, to add a new line 3 in thedocument, the user can input or otherwise place a carriage return (e.g.,line break) at the end of line 2 in the document. In other words, theaddition of new line 3 in the document is a result of an edit to line 2(to input the carriage return). In response to detecting the edit tolines 2 and 3, text editing application 502 may create an edit operationrecord 816 to record the change to the document resulting from the editto lines 2 and 3.

To this end, as can be seen in FIG. 8D, text editing application 502 mayinclude in edit operation record 816 a description of the change tolines 2 and 3 (denoted C4 in FIG. 8D), and set the line start value toline 2 (LS: 2) and the line end value to line 3 (LE: 3). Line startvalue of 2 and line end value of 3 indicates that the edit to add newline 3 starts at line 2 in the document and ends at line 3 in thedocument. Note that the addition of new line 3 in the document causesthe lines of text lower than new line 3 in the document (i.e., originallines 3 and higher) to shift down by one line.

Text editing application 502 may check to determine whether the editoperation (i.e., either change to line 2 or newly added line 3) is orotherwise occurs in an existing dynamic region or within a thresholdrange of an existing dynamic region in the document. At this point, thedocument includes dynamic region A as defined by dynamic region A datastructure 804A, dynamic region B as defined by dynamic region B datastructure 804B, and dynamic region C as defined by dynamic region C datastructure 804C. Text editing application 502 may determine that thechanged line 2 is within the threshold range of dynamic region A. Morespecifically, changed line 2 is within the threshold range of line 1which is the actual end line number of dynamic region A as indicated bydynamic region A data structure 804A (i.e., RE: 1+Off: 0=line 1). As aresult of this determination, as can be seen in FIG. 8D, text editingapplication 502 may push edit operation record 816 onto the top ofdynamic region A undo stack 806A.

Note that the edit to add new line 3 in this manner added two lines todynamic region A. That is, the edit to add new line 3 by changing line 2to insert new line 3 causes an increase of two lines (lines 2 and 3) indynamic region A. Accordingly, text editing application 502 may set theregion end value to line 3 (RE: 3) in dynamic region A data structure804A to indicate the new end location of dynamic region A as a result ofthe edit operation to add new line 3. As the last executed editoperation in dynamic region A, the edit operation (i.e., the change tolines 2 and 3 as recorded in edit operation record 816) can be poppedfrom the top of dynamic region A undo stack 806A and undone. Note thatthe edit to line 1 recorded by edit operation record 810 cannot beundone since edit operation record 810 is no longer at the top ofdynamic region A undo stack 806A. In order to undo the edit to line 1,the edit operation recorded in edit operation record 816 (i.e., the editto add new line 3) needs to be undone first, which will place editoperation record 810 at the top of dynamic region A undo stack 806A.

Since the edit operation resulted in an addition of lines to thedocument, text editing application 502 may check to determine whether adynamic region in the document is located below dynamic region A, whichnow hosts the edit to include new line 3. At this point, other thandynamic region A, the document also includes dynamic region B as definedby dynamic region B data structure 804B and dynamic region C as definedby dynamic region C data structure 804C. Text editing application 502may determine that both dynamic region B and dynamic region C arelocated below dynamic region A in the document. As a result of thisdetermination, text editing application 502 may adjust the respectiveregion offset values for dynamic region B and dynamic region C toaccount for the number of lines added in dynamic region A. For instance,since one line (i.e., a new line 3) was added to dynamic region A, textediting application 502 may increment or increase the region offsetvalue in dynamic region B data structure 804B by one (i.e., from Off: 0to Off: 1). Text editing application 502 may also increment or increasethe region offset value in dynamic region C data structure 804C by one(i.e., from Off: 0 to Off: 1).

Continuing the example use case, the user may then make an edit to thetext in line 21 of the document. Note that line 21 in the document wasoriginal line 20 prior to the user making the prior edit to add the newline 3 in the document. In response to detecting the edit to line 21,text editing application 502 may create an edit operation record 818 torecord the change to the document resulting from the edit to line 21.

To this end, as can be seen in FIG. 8E, text editing application 502 mayinclude in edit operation record 818 a description of the change to line21 (denoted C5 in FIG. 8E), and set the line start value to line 21 (LS:21) and the line end value to line 21 (LE: 21). Since the resultingchange is to a single line (line 21), the line start value is the sameas the line end value.

Text editing application 502 may check to determine whether the editoperation (i.e., change to line 21) is or otherwise occurs in anexisting dynamic region or within a threshold range of an existingdynamic region in the document. At this point, the document includesdynamic region A as defined by dynamic region A data structure 804A,dynamic region B as defined by dynamic region B data structure 804B, anddynamic region C as defined by dynamic region C data structure 804C.Note that dynamic region A has a region offset value of zero (Off: 0),and dynamic region B and dynamic region C both have a region offsetvalue of one (Off: 1). The non-zero region offset value affects theactual locations of dynamic region B and dynamic region C in thedocument. Due to the non-zero region offset value, the actual locationof dynamic region B in the document starts at line 8 (i.e., actual startline number of RS: 7+Off: 1) and ends at line 8 (i.e., actual end linenumber of RE: 7+Off: 1), and the actual location of dynamic region C inthe document starts at line 21 (i.e., actual start line number of RS:20+Off: 1) and ends at line 21 (i.e., actual end line number of RE:20+Off: 1). The actual location of dynamic region A in the documentstarts at line 1 (i.e., actual start line number of RS: 1+Off: 0) andends at line 3 (i.e., actual end line number of RE: 3+Off: 0) asreflected by the current RS and RE values in dynamic region A datastructure 804A. Based on the actual locations of the dynamic regions inthe document, text editing application 502 may determine that thechanged line 21 is in dynamic region C as indicated by dynamic region Cdata structure 804C. However, since the non-zero region offset value ofdynamic region C affects the actual location of the edit operation toline 21, the location of the edit to line 21 as recorded in editoperation record 818 needs to be adjusted to account for the non-zeroregion offset value of dynamic region C. Hence, text editing application502 may create an edit operation record 818 a that reflects theappropriate adjustment to the line start value and the line end value.

As can be seen in FIG. 8E, text editing application 502 may include inedit operation record 818 a a description of the change to line 21, andset the line start value to line 20 (i.e., decrease the line start valuein edit operation record 818 by the number of lines added in dynamicregion A) and the line end value to line 20 (i.e., decrease the linestart value in edit operation record 818 by the number of lines added indynamic region A). Text editing application 502 may push edit operationrecord 818 a onto the top of dynamic region C undo stack 806C. As thelast executed edit operation in dynamic region C, the edit operation(i.e., the change to line 20 as recorded in edit operation record 818 a)can be popped from the top of dynamic region C undo stack 806C andundone. Note that the actual location of the edit operation is line 21(i.e., RS: 20+Off: 1) because of the region offset value of oneassociated with dynamic region C.

The user may continue to make edits to the document during the documentediting session. For example, as can be seen in FIGS. 9A and 9B, theuser may make an edit to the document to delete line 13. In particular,as can be seen in FIG. 9A which shows a portion of the document beforethe user's edit, the document includes a line 13 which is a blank line(see reference numeral 902) between line 12 having the text“Environment:” (see reference numeral 904) and line 14 having the text“Kernel-mode Driver Framework” (see reference numeral 906). As can beseen in FIG. 9B which shows the portion of the document after the user'sedit, the document no longer includes original line 13 (i.e., the blankline) that existed in the document before the edit to delete line 13.Rather, original line 14 having the text Kernel-mode Driver Framework”(see reference numeral 906) now immediately follows line 12 (seereference numeral 904) as new line 13. More generally, all the lines inthe document located below deleted original line 13 move or shift up oneline in the document.

To delete line 13 in the document, the user deleted or otherwise removedthe carriage return (e.g., line break) which was at the end of line 12.In other words, the deletion of original line 13 in the document in aresult of an edit to line 12 (to delete the carriage return) in thedocument. In an implementation, as shown in FIG. 9B, the change to line12 may be indicated by a change bar 908 displayed in the margin of thedocument next to line 12. More generally, similar change bars may bedisplayed in the margin of the document to indicate the lines of text inthe document that have changed during the editing session.

Referring now to FIG. 10, in response to detecting the edit to line 12and deleted original line 13, text editing application 502 may create anedit operation record 820 to record the change to the document. To thisend, text editing application 502 may include in edit operation record820 a description of the change to line 12 and deleted original line 13(denoted C6 in FIG. 10), and set the line start value to line 12 (LS:12) and the line end value to line 13 (LE: 13), which is the line thatis deleted by the edit operation. Line start value of 12 and line endvalue of 13 indicates that the edit to delete original line 3 starts atline 12 in the document and ends at line 13 in the document.

Still referring to FIG. 10, text editing application 502 may check todetermine whether the edit operation (i.e., either change to line 12 ordeleted original line 13) is or otherwise occurs in an existing dynamicregion in the document. At this point, the document includes dynamicregion A as defined by dynamic region A data structure 804A, dynamicregion B as defined by dynamic region B data structure 804B, and dynamicregion C as defined by dynamic region C data structure 804C. Asdescribed previously, due to the non-zero region offset values, theactual location of dynamic region B in the document starts at line 8(i.e., actual start line number of RS: 7+Off: 1) and ends at line 8(i.e., actual end line number of RE: 7+Off: 1), and the actual locationof dynamic region C in the document starts at line 21 (i.e., actualstart line number of RS: 20+Off: 1) and ends at line 21 (i.e., actualend line number of RE: 20+Off: 1). The actual location of dynamic regionA in the document starts at line 1 (i.e., actual start line number ofRS: 1+Off: 0) and ends at line 3 (i.e., actual end line number of RE:3+Off: 0) as reflected by the current RS and RE values in dynamic regionA data structure 804A. Based on the actual locations of the dynamicregions in the document, text editing application 502 may determine thatthe changed line 12 or deleted original line 13 is not within dynamicregion A, dynamic region B, or dynamic region C. As a result of thisdetermination, text editing application 502 may create a dynamic regionD for this edit operation (i.e., delete original line 13). To this end,text editing application 502 may create a dynamic region D datastructure 804D, a dynamic region D undo stack 806D, and a dynamic regionD redo stack 808D. Dynamic region D data structure 804D defines dynamicregion D created to host the edit to line 12 to delete original line 13.Accordingly, text editing application 502 may set the region start valueto line 12 (RS: 12), the region end value to line 12 (RE: 12), and theregion offset value to zero (Off: 0). In other words, at this point,dynamic region D includes only line 12 which was changed to cause thedeletion of original line 13. Text editing application 502 may push editoperation record 820 onto the top of dynamic region D undo stack 806D.As the last executed edit operation in dynamic region D, the editoperation (i.e., the change to line 12 to add a new line 13 as recordedin edit operation record 820) can be popped from the top of dynamicregion D undo stack 806D and undone.

Since the edit operation to delete original line 13 resulted in adeletion of one line from the document, text editing application 502 maycheck to determine whether a dynamic region in the document is locatedbelow dynamic region D, which now hosts the edit to delete original line13. At this point, other than dynamic region D, the document alsoincludes dynamic region A as defined by dynamic region A data structure804A, dynamic region B as defined by dynamic region B data structure804B, and dynamic region C as defined by dynamic region C data structure804C. Based on the actual locations of dynamic region A, dynamic regionB, and dynamic region C, text editing application 502 may determine thatdynamic region C is located below dynamic region D in the document. As aresult of this determination, text editing application 502 may adjustthe region offset value for dynamic region C to account for the numberof lines deleted in the document by the edit operation hosted in dynamicregion D. For instance, since one line (i.e., deletion of original line13) was deleted in the document, text editing application 502 maydecrease the region offset value in dynamic region C data structure 804Cby one (i.e., from Off: 1 to Off: 0). Decreasing the region offset valueof dynamic region C in this manner accounts for the upshifting of thelines of text included in dynamic region C as a result of the deletionof original line 13 as recorded in edit operation record 820.

Continuing the example use case, the user may then make an edit to thetext in lines 4-7 of the document. Note that lines 4-7 in the documentwere original lines 3-6 prior to the user making the prior edit to addthe new line 3 in the document. In response to detecting the edit tolines 4-7, text editing application 502 may create an edit operationrecord 822 to record the change to the document resulting from the editto lines 4-7. To this end, as can be seen in FIG. 11, text editingapplication 502 may include in edit operation record 822 a descriptionof the change to lines 4-7 (denoted C7 in FIG. 11), and set the linestart value to line 4 (LS: 4) and the line end value to line 7 (LE: 7).Line start value of 4 and line end value of 7 indicates that the edit tolines 4-7 starts at line 4 in the document and ends at line 7 in thedocument.

Text editing application 502 may check to determine whether the editoperation (i.e., either change to line 4, line 5, line 6, or line 7) isor otherwise occurs in an existing dynamic region or within a thresholdrange of an existing dynamic region in the document. At this point, thedocument includes dynamic region A as defined by dynamic region A datastructure 804A, dynamic region B as defined by dynamic region B datastructure 804B, dynamic region C as defined by dynamic region C datastructure 804C, and dynamic region D as defined by dynamic region D datastructure 804D. Based on the actual locations of the dynamic regions inthe document, text editing application 502 may determine that thechanged line 4 is within the threshold range of dynamic region A. Textediting application 502 may determine also that the changed line 7 iswithin the threshold range of dynamic region B. In an implementation, incases where an edit operation is within the threshold range of multipledynamic regions in a document, text editing application 502 may selectthe dynamic region that is located higher in the document (i.e., thedynamic region with the smaller region start value). As a result of thisdetermination, text editing application 502 may push edit operationrecord 822 onto the top of dynamic region A undo stack 806A. It will beappreciated in light of this disclosure that, in other implementations,text editing application 502 may select the dynamic region that islocated lower in the document (i.e., the dynamic region with the higherregion start value) or arbitrarily select a dynamic region from themultiple dynamic regions to host an edit operation that is within thethreshold range of multiple dynamic regions.

Note that, since the edit operation (edit to the text in lines 4-7) and,more specifically, the changed line 7, is also within the thresholdrange of dynamic region B, the edit operation results in a merging ofdynamic region A and dynamic region B. Since dynamic region A isselected to host the edit operation, dynamic region B can be treated asbeing merged into dynamic region A. To this end, the end location ofdynamic region A is adjusted to reflect the combined scope of dynamicregion A and dynamic region B. Here, because of the non-zero regionoffset value of dynamic region B (i.e., dynamic region B has a regionoffset value of 1), the actual location of dynamic region B in thedocument starts at line 8 (i.e., actual start line number of RS:7+Off: 1) and ends at line 8 (i.e., actual end line number of RE: 7+Off:1). Accordingly, as can be seen in FIG. 11, text editing application 502may set the region end value to line 8 (RE: 8) in dynamic region A datastructure 804A to indicate the new end location of dynamic region A as aresult of the merging of dynamic region B into dynamic region A.

FIGS. 12A and 12B more clearly show an example of the merging of dynamicregions in a document. As can be seen in FIG. 12A which shows a portionof the document before the user's edit to lines 4-7 and resultingmerging of dynamic region A and dynamic region B, the document includesdynamic region A (see reference numeral 1202) and dynamic region B (seereference numeral 1204). In an implementation, a change bar 1206 may bedisplayed in the margin of the document next to lines 1-3 to indicatethat changes have been made to lines 1-3 in dynamic region A. Likewise,a change bar 1208 may be displayed in the margin of the document next toline 8 to indicate that changes have been made to line 8 in dynamicregion B (as noted above, due to the non-zero region offset value, theactual location of dynamic region B in the document is line 8). As canbe seen in FIG. 12B which shows the portion of the document after theuser's edit to lines 4-7 and resulting merging of dynamic region A anddynamic region B, the document includes a new dynamic region A thatincludes dynamic region B (see reference numeral 1210). A change bar1212 may be displayed in the margin of the document next to lines 1-8 toindicate that changes have been made to lines 1-8 in the new dynamicregion A.

Referring again to FIG. 11, since the scope of dynamic region B is nowcovered by dynamic region A, text editing application 502 may treatdynamic region B as a dormant or inactive dynamic region in the document(e.g., as indicated by the dashed lines for dynamic region B datastructure 804B, dynamic region B undo stack 806B, and dynamic region Bredo stack 808B). As can be seen in FIG. 11, the values in dynamicregion B data structure 804B and the contents of dynamic region B undostack 806B and dynamic region B redo stack 808B remain unchanged. Thisallows dynamic region B to become active again once the edit operation(i.e., the edit to the text in lines 4-7 as recorded in edit operationrecord 822) that caused the merging of dynamic region B into dynamicregion A is undone. For instance, popping edit operation record 822 fromthe top of dynamic region A undo stack 806A and undoing the change tolines 4-7 undoes the merging of dynamic region A and dynamic region B.In other words, undoing the change to lines 4-7 as recorded in editoperation record 822 causes dynamic region A to be split back intodynamic region A and dynamic region B.

Continuing the example use case, the user may request an undo of an editmade in a particular dynamic region in the document. To trigger an undoaction in a dynamic region, in an implementation, the user can use apointing device or keyboard to move a cursor to a location near or nextto the desired dynamic region (e.g., near or next to a change bardisplayed next to the change lines). For example, the user may triggeran undo of an edit made in dynamic region C. Upon the user triggeringthe undo action, text editing application 502 may identify theparticular dynamic region in which to perform the undo operation basedon the location of the cursor. In this example case, text editingapplication 502 may identify dynamic region C as the dynamic region inwhich to perform the undo operation. To perform the undo operation indynamic region C, as can be seen in FIG. 13, text editing application502 may pop edit operation record 818 a from the top of dynamic region Cundo stack 806C, perform the inverse of the edit operation recorded inedit operation record 818 a, and push edit operation record 818 a ontothe top of dynamic region C redo stack 808C. As previously described,edit operation record 818 a recorded a change to line 21. As such,performing the inverse of the edit operation recorded in edit operationrecord 818 a undoes the change made to line 21 at the time of performingthe edit operation. However, at this point, the actual location in thedocument to perform the inverse of the recorded edit operation isindicated by the line start value in edit operation record 818 a (LS:20) and the line end value in edit operation record 818 a (LE: 20)adjusted by the dynamic region C region offset value in dynamic region Cdata structure 804C (Off: 0). Based on these values, the actual locationin the document to perform the inverse edit operation is line 20 (actualline numbers LS: 20+Off: 0 to LE:20+Off: 0). Computing the actual linenumber to perform the inverse of the recorded edit operation in thismanner accounts for the upshifting of the lines of text included indynamic region C as a result of the deletion of original line 13 asrecorded in edit operation record 820. Since performing the inverse ofthe edit operation recorded in edit operation record 818 a did notresult in an addition or deletion of lines in the document, text editingapplication 502 does not have to check for dynamic regions located belowdynamic region C in the document.

Continuing the example use case, the user may request an undo of an editmade in dynamic region A in the document. Upon the user triggering theundo action, text editing application 502 may identify dynamic region Aas the dynamic region in which to perform the undo operation. To performthe undo operation in dynamic region A, as can be seen in FIG. 14, textediting application 502 may pop edit operation record 822 from the topof dynamic region A undo stack 806A, perform the inverse of the editoperation recorded in edit operation record 822, and push edit operationrecord 822 onto the top of dynamic region A redo stack 808A. Aspreviously described, edit operation record 822 recorded a change tolines 4-7. As such, performing the inverse of the edit operationrecorded in edit operation record 822 undoes the change made to lines4-7 at the time of performing the edit operation. However, at thispoint, the actual location in the document to perform the inverse of therecorded edit operation is indicated by the line start value in editoperation record 822 (LS: 4) and the line end value in edit operationrecord 822 (LE: 7) adjusted by the dynamic region A region offset valuein dynamic region A data structure 804A (Off: 0). Based on these values,the actual location in the document to perform the inverse editoperation is lines 4-7 (actual line numbers LS: 4+Off: 0 to LE:7+Off:0). Computing the actual line number to perform the inverse of therecorded edit operation in this manner accounts for the upshifting ofthe lines of text included in dynamic region C as a result of thedeletion of original line 13 as recorded in edit operation record 820.Since performing the inverse of the edit operation recorded in editoperation record 822 did not result in an addition or deletion of linesin the document, text editing application 502 does not have to check fordynamic regions located below dynamic region C in the document.

Note that undoing the changes to lines 4-7 as recorded in edit operationrecord 822 changes the scope of dynamic region A to no longer includelines 4-7. Note also that undoing the changes to lines 4-7 and thusremoving lines 4-7 from the scope of dynamic region A undoes the mergingof dynamic region A and dynamic region B. To this end, text editingapplication 502 may set the region end value to line 3 (RE: 3) indynamic region A data structure 804A to indicate the separation orsplitting of dynamic region B and the undoing of the changes to lines4-7. Text editing application 502 may again treat dynamic region B as anactive dynamic region in the document (e.g., as indicated by the solidlines for dynamic region B data structure 804B, dynamic region B undostack 806B, and dynamic region B redo stack 808B).

It will be appreciated in light of this disclosure that a redo operationin a particular dynamic region may be processed by popping an editoperation record from the top of an undo stack for the particulardynamic region, performing the edit operation recorded in the poppededit operation record, and pushing the popped edit operation record ontothe top of an undo stack for the particular dynamic region. As will befurther described below at least in conjunction with FIG. 17, the redooperation may be processed in the same or substantially the same manneras edit operations and/or undo operations.

FIG. 15 is a flow diagram of an example process 1500 for processing amodification to a document, in accordance with an embodiment of thepresent disclosure. Example process 1500, and example processes 1600 and1700 further described below, may be implemented or used within acomputing environment or system such as those disclosed above at leastwith respect to FIG. 2, FIG. 3, and/or FIGS. 4A-4C. For example, in someembodiments, the operations, functions, or actions illustrated inexample process 1500, and example processes 1600 and 1700 furtherdescribed below, may be stored as computer-executable instructions in acomputer-readable medium, such as volatile memory 122 and/ornon-volatile memory 128 of computing device 100 of FIG. 2 (e.g.,computer-readable medium of client machines 102 of FIG. 1, clientmachines 102 a-102 n of FIG. 3 and/or clients 202 of FIGS. 4A-4C). Insome embodiments, example process 1500, and example processes 1600 and1700 further described below, may be implemented by applicationsoftware, such as text editing application 502, which may run on asuitable computing device, such as computing device 100 of FIG. 2,client machines 102 a-102 n of FIG. 3, and/or clients 202 of FIGS.4A-4C. For example, the operations, functions, or actions described inthe respective blocks of example process 1500, and example processes1600 and 1700 further described below, may be implemented byapplications 116 and/or data 117 of computing device 100. Although thefollowing description of processes 1500, 1600, and 1700 may refer todocuments, it is appreciated herein that the processes can be applied toother types of text-based content.

With reference to FIG. 15, process 1500 is initiated and, at 1502,application software, such as text editing application 502, may detect amodification in a dynamic region in a document. For example, a user maybe using text editing application to edit the contents of a document.

At 1504, text editing application 502 may create an edit operationrecord and record the modification to the document in the created editoperation record. Text editing application 502 may then push the creatededit operation record onto an undo stack associated with the dynamicregion in which the modification is made.

At 1506, text editing application 502 may check to determine whether themodification in the dynamic region causes or otherwise results in anaddition of lines in the dynamic region. If the modification results inan addition of lines in the dynamic region, then, at 1508, text editingapplication 502 may compute or otherwise determine a count of the numberof lines that are added by the modification.

At 1510, text editing application 502 may increase a region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines added in the dynamic region by themodification. In an embodiment, text editing application 502 maymaintain the dynamic region location information, including the regionend value, in a dynamic region data structure.

At 1512, text editing application 502 may identify dynamic regions inthe document located below the dynamic region in which the modificationis made. For the identified dynamic regions, text editing application502 may increase a respective region offset value for the dynamicregions by the count of the number of lines added in the dynamic regionby the modification. The respective region offset values are used toresolve the edit dependency issue across the dynamic regions in thedocument. In an embodiment, text editing application 502 may maintainthe region offset values in the respective dynamic region datastructures created for the dynamic regions in the document. Process 1500may then end.

If the modification does not result in an addition of lines in thedynamic region, then, at 1514, text editing application 502 may check todetermine whether the modification in the dynamic region causes orotherwise results in a deletion of lines in the dynamic region. If themodification results in a deletion of lines in the dynamic region, then,at 1516, text editing application 502 may compute or otherwise determinea count of the number of lines that are deleted by the modification.

At 1518, text editing application 502 may decrease the region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines deleted in the dynamic region by themodification. At 1520, text editing application 502 may identify dynamicregions in the document located below the dynamic region in which themodification is made. For the identified dynamic regions, text editingapplication 502 may decrease the respective region offset value for thedynamic regions by the count of the number of lines deleted in thedynamic region by the modification. Process 1500 may then end.

Otherwise, if, at 1514, the modification does not result in a deletionof lines in the dynamic region, process 1500 may end. In this case,since the modification does not result in either an addition of lines ora deletion of lines in the dynamic region, no adjustment of the regionend value of the dynamic region or the region offset values for thedynamic regions located below the dynamic region in which themodification is made is needed.

FIG. 16 is a flow diagram of an example process 1600 for processing anundo operation, in accordance with an embodiment of the presentdisclosure. Process 1600 is initiated and, at 1602, applicationsoftware, such as text editing application 502, may detect an undooperation in a dynamic region in a document. For example, a user may beusing text editing application to edit the contents of a document and,during an editing session, trigger an undo action in the dynamic regionin the document.

At 1604, text editing application 502 may pop an edit operation recordfrom the top of an undo stack associated with the dynamic region inwhich the undo action is detected. The edit operation record may recorda prior modification made to the document. At 1606, text editingapplication 502 may cause the undo operation to be performed. Morespecifically, text editing application 502 may cause an inverse of themodification recorded in the popped edit operation record to beperformed. At 1608, text editing application 502 may push the poppededit operation record onto a redo stack associated with the dynamicregion in which the undo action is detected.

At 1610, text editing application 502 may check to determine whether theundo operation in the dynamic region causes or otherwise results in anaddition of lines in the dynamic region. If the undo operation resultsin an addition of lines in the dynamic region, then, at 1612, textediting application 502 may compute or otherwise determine a count ofthe number of lines that are added by the undo operation.

At 1614, text editing application 502 may increase a region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines added in the dynamic region by the undooperation. In an embodiment, text editing application 502 may maintainthe dynamic region location information, including the region end value,in a dynamic region data structure.

At 1616, text editing application 502 may identify dynamic regions inthe document located below the dynamic region in which the undooperation is performed. For the identified dynamic regions, text editingapplication 502 may increase a respective region offset value for thedynamic regions by the count of the number of lines added in the dynamicregion by the undo operation. In an embodiment, text editing application502 may maintain the region offset values in the respective dynamicregion data structures created for the dynamic regions in the document.Process 1600 may then end.

If the undo operation does not result in an addition of lines in thedynamic region, then, at 1618, text editing application 502 may check todetermine whether the undo operation in the dynamic region causes orotherwise results in a deletion of lines in the dynamic region. If theundo operation results in a deletion of lines in the dynamic region,then, at 1620, text editing application 502 may compute or otherwisedetermine a count of the number of lines that are deleted by the undooperation.

At 1622, text editing application 502 may decrease the region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines deleted in the dynamic region by the undooperation. At 1624, text editing application 502 may identify dynamicregions in the document located below the dynamic region in which theundo operation is performed. For the identified dynamic regions, textediting application 502 may decrease the respective region offset valuefor the dynamic regions by the count of the number of lines deleted inthe dynamic region by the undo operation. Process 1600 may then end.

Otherwise, if, at 1618, the undo operation does not result in a deletionof lines in the dynamic region, process 1600 may end. In this case,since the performance of the undo operation does not result in either anaddition of lines or a deletion of lines in the dynamic region, noadjustment of the region end value of the dynamic region or the regionoffset values for the dynamic regions located below the dynamic regionin which the undo operation is performed is needed.

FIG. 17 is a flow diagram of an example process 1700 for processing aredo operation, in accordance with an embodiment of the presentdisclosure. Process 1700 is initiated and, at 1702, applicationsoftware, such as text editing application 502, may detect a redooperation in a dynamic region in a document. For example, a user may beusing text editing application to edit the contents of a document and,during an editing session, trigger a redo action in the dynamic regionin the document.

At 1704, text editing application 502 may pop an edit operation recordfrom the top of a redo stack associated with the dynamic region in whichthe redo action is detected. The edit operation record may record aprior modification made to the document and which was previously undoneby execution of an undo operation. At 1706, text editing application 502may cause the redo operation to be performed. More specifically, textediting application 502 may cause the previously undone operation to beredone. At 1708, text editing application 502 may push the popped editoperation record onto an undo stack associated with the dynamic regionin which the redo action is detected.

At 1710, text editing application 502 may check to determine whether theredo operation in the dynamic region causes or otherwise results in anaddition of lines in the dynamic region. If the redo operation resultsin an addition of lines in the dynamic region, then, at 1712, textediting application 502 may compute or otherwise determine a count ofthe number of lines that are added by the redo operation.

At 1714, text editing application 502 may increase a region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines added in the dynamic region by the redooperation. In an embodiment, text editing application 502 may maintainthe dynamic region location information, including the region end value,in a dynamic region data structure.

At 1716, text editing application 502 may identify dynamic regions inthe document located below the dynamic region in which the redooperation is performed. For the identified dynamic regions, text editingapplication 502 may increase a respective region offset value for thedynamic regions by the count of the number of lines added in the dynamicregion by the redo operation. In an embodiment, text editing application502 may maintain the region offset values in the respective dynamicregion data structures created for the dynamic regions in the document.Process 1700 may then end.

If the redo operation does not result in an addition of lines in thedynamic region, then, at 1718, text editing application 502 may check todetermine whether the redo operation in the dynamic region causes orotherwise results in a deletion of lines in the dynamic region. If theredo operation results in a deletion of lines in the dynamic region,then, at 1720, text editing application 502 may compute or otherwisedetermine a count of the number of lines that are deleted by the redooperation.

At 1722, text editing application 502 may decrease the region end valuethat indicates the end of the dynamic region in the document by thecount of the number of lines deleted in the dynamic region by the redooperation. At 1724, text editing application 502 may identify dynamicregions in the document located below the dynamic region in which theredo operation is performed. For the identified dynamic regions, textediting application 502 may decrease the respective region offset valuefor the dynamic regions by the count of the number of lines deleted inthe dynamic region by the redo operation. Process 1700 may then end.

Otherwise, if, at 1718, the redo operation does not result in a deletionof lines in the dynamic region, process 1700 may end. In this case,since the performance of the redo operation does not result in either anaddition of lines or a deletion of lines in the dynamic region, noadjustment of the region end value of the dynamic region or the regionoffset values for the dynamic regions located below the dynamic regionin which the redo operation is performed is needed.

FURTHER EXAMPLE EMBODIMENTS

The following examples pertain to further embodiments, from whichnumerous permutations and configurations will be apparent.

Example 1 includes a method including: providing a data structure for aregion of a document, the data structure including a start value, an endvalue, and an offset value that define the region within the document;and, responsive to detection of a modification of content within theregion, determining a count of the number of lines of the documentwithin the region; adjusting at least one of the start value, the endvalue, and the offset value of the region to change an area of theregion based on the count of the number of lines; and pushing a recordof the modification onto a stack of the region in response to themodification of content within the region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.

Example 2 includes the subject matter of Example 1, wherein themodification results in an addition of at least one line in the region.

Example 3 includes the subject matter of Example 1, wherein themodification results in a deletion of at least one line in the region.

Example 4 includes the subject matter of any of Examples 1 through 3,wherein the stack is one of an undo stack or a redo stack.

Example 5 includes the subject matter of any of Examples 1 through 4,wherein the modification is an undo operation and the stack is a redostack.

Example 6 includes the subject matter of any of Examples 1 through 4,wherein the modification is a redo operation and the stack is an undostack.

Example 7 includes the subject matter of any of Examples 1 through 6,further including: responsive to detection of a modification of contentthat adds or deletes at least one line within a second region of thedocument located above the first region of the document, adjusting theoffset value of the first region to change an area of the first regionbased on the modification of content within the second region.

Example 8 includes the subject matter of any of Examples 1 through 7,wherein the modification results in a merging of an adjacent region ofthe document and the region.

Example 9 includes a system including a memory and one or moreprocessors in communication with the memory and configured to: provide adata structure for a region of a document, the data structure includinga start value, an end value, and an offset value that define the regionwithin the document; and, responsive to detection of a modification ofcontent within the region, determine a count of the number of lines ofthe document within the region; adjust at least one of the start value,the end value, and offset value of the region to change an area of theregion based on the count of the number of lines; and push a record ofthe modification onto a stack of the region in response to themodification of content within the region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.

Example 10 includes the subject matter of Example 9, wherein themodification is an undo operation and the stack is a redo stack.

Example 11 includes the subject matter of Example 9, wherein themodification is a redo operation and the stack is an undo stack.

Example 12 includes the subject matter of any of Examples 9 through 11,wherein the modification results in an addition of at least one line inthe region.

Example 13 includes the subject matter of any of Examples 9 through 11,wherein the modification results in a deletion of at least one line inthe region.

Example 14 includes the subject matter of any of Examples 9 through 13,the one or more processors further configured to: responsive todetection of a modification of content that adds or deletes at least oneline within a second region of the document located above the firstregion of the document, adjust the offset value of the first region tochange an area of the first region based on the modification of contentwithin the second region.

Example 15 includes the subject matter of any of Examples 9 through 14,wherein the modification results in a merge of an adjacent region of thedocument and the region.

Example 16 includes a method including: providing a first data structurefor a first region of a document, the first data structure including astart value, an end value, and an offset value that define the firstregion within the document; providing a second data structure for asecond region of a document below the first region, the second datastructure including a start value, an end value, and an offset valuethat define the second region within the document; and, responsive todetection of a modification of content within the first region,determining a count of the number of lines added or deleted in the firstregion; adjusting at least one of the start value and the end value ofthe of the first region based on the modification of content within thefirst region; and adjusting the offset value of the second region tochange an area of the second region based on the count of the number oflines added or deleted in the first region.

Example 17 includes the subject matter of Example 16, further including:responsive to detection of the modification of content within the firstregion, pushing a record of the modification onto a stack of the firstregion in response to the modification of content within the firstregion, the stack configured to receive elements representative ofindividual actions to be performed on content within the first region ofthe document, so as to enable the modification to be undone or redone ina non-linear fashion.

Example 18 includes the subject matter of any of Examples 16 and 17,wherein the stack is an undo stack.

Example 19 includes the subject matter of any of Examples 16 and 17,wherein the stack is a redo stack.

Example 20 includes the subject matter of any of Examples 16 through 19,wherein the modification results in an addition of at least one line inthe region.

Example 21 includes the subject matter of any of Examples 16 through 19,wherein the modification results in a deletion of at least one line inthe region.

Example 22 includes the subject matter of any of Examples 16 through 21,wherein the modification results in a merging of the first region andthe second region.

Example 23 includes a system including a memory and one or moreprocessors in communication with the memory and configured to: provide afirst data structure for a first region of a document, the first datastructure including a start value, an end value, and an offset valuethat define the first region within the document; provide a second datastructure for a second region of a document below the first region, thesecond data structure including a start value, an end value, and anoffset value that define the second region within the document; and,responsive to detection of a modification of content within the firstregion, determine a count of the number of lines added or deleted in thefirst region; adjust at least one of the start value and the end valueof the of the first region based on the modification of content withinthe first region; and adjust the offset value of the second region tochange an area of the second region based on the count of the number oflines added or deleted in the first region.

Example 24 includes the subject matter of Example 23, the one or moreprocessors further configured to: responsive to detection of themodification of content within the first region, push a record of themodification onto a stack of the first region in response to themodification of content within the first region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the first region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.

Example 25 includes the subject matter of any of Examples 23 and 24,wherein the stack is an undo stack.

Example 26 includes the subject matter of any of Examples 23 and 24,wherein the stack is a redo stack.

Example 27 includes the subject matter of any of Examples 23 through 26,wherein the modification results in an addition of at least one line inthe region.

Example 28 includes the subject matter of any of Examples 23 through 26,wherein the modification results in a deletion of at least one line inthe region.

Example 29 includes the subject matter of any of Examples 23 through 28,wherein the modification results in a merging of the first region andthe second region.

As will be further appreciated in light of this disclosure, with respectto the processes and methods disclosed herein, the functions performedin the processes and methods may be implemented in differing order.Additionally or alternatively, two or more operations may be performedat the same time or otherwise in an overlapping contemporaneous fashion.Furthermore, the outlined actions and operations are only provided asexamples, and some of the actions and operations may be optional,combined into fewer actions and operations, or expanded into additionalactions and operations without detracting from the essence of thedisclosed embodiments.

In the description of the various embodiments, reference is made to theaccompanying drawings identified above and which form a part hereof, andin which is shown by way of illustration various embodiments in whichaspects of the concepts described herein may be practiced. It is to beunderstood that other embodiments may be utilized, and structural andfunctional modifications may be made without departing from the scope ofthe concepts described herein. It should thus be understood that variousaspects of the concepts described herein may be implemented inembodiments other than those specifically described herein. It shouldalso be appreciated that the concepts described herein are capable ofbeing practiced or being carried out in ways which are different thanthose specifically described herein.

As used in the present disclosure, the terms “engine” or “module” or“component” may refer to specific hardware implementations configured toperform the actions of the engine or module or component and/or softwareobjects or software routines that may be stored on and/or executed bygeneral purpose hardware (e.g., computer-readable media, processingdevices, etc.) of the computing system. In some embodiments, thedifferent components, modules, engines, and services described in thepresent disclosure may be implemented as objects or processes thatexecute on the computing system (e.g., as separate threads). While someof the system and methods described in the present disclosure aregenerally described as being implemented in software (stored on and/orexecuted by general purpose hardware), specific hardwareimplementations, firmware implements, or any combination thereof arealso possible and contemplated. In this description, a “computingentity” may be any computing system as previously described in thepresent disclosure, or any module or combination of modulates executingon a computing system.

Terms used in the present disclosure and in the appended claims (e.g.,bodies of the appended claims) are generally intended as “open” terms(e.g., the term “including” should be interpreted as “including, but notlimited to,” the term “having” should be interpreted as “having atleast,” the term “includes” should be interpreted as “includes, but isnot limited to,” etc.).

Additionally, if a specific number of an introduced claim recitation isintended, such an intent will be explicitly recited in the claim, and inthe absence of such recitation no such intent is present. For example,as an aid to understanding, the following appended claims may containusage of the introductory phrases “at least one” and “one or more” tointroduce claim recitations. However, the use of such phrases should notbe construed to imply that the introduction of a claim recitation by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitationis explicitly recited, such recitation should be interpreted to mean atleast the recited number (e.g., the bare recitation of “two widgets,”without other modifiers, means at least two widgets, or two or morewidgets). Furthermore, in those instances where a convention analogousto “at least one of A, B, and C, etc.” or “one or more of A, B, and C,etc.” is used, in general such a construction is intended to include Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, or A, B, and C together, etc.

It is to be understood that the phraseology and terminology used hereinare for the purpose of description and should not be regarded aslimiting. Rather, the phrases and terms used herein are to be giventheir broadest interpretation and meaning. The use of “including” and“comprising” and variations thereof is meant to encompass the itemslisted thereafter and equivalents thereof as well as additional itemsand equivalents thereof. The use of the terms “connected,” “coupled,”and similar terms, is meant to include both direct and indirect,connecting, and coupling.

All examples and conditional language recited in the present disclosureare intended for pedagogical examples to aid the reader in understandingthe present disclosure, and are to be construed as being withoutlimitation to such specifically recited examples and conditions.Although example embodiments of the present disclosure have beendescribed in detail, various changes, substitutions, and alterationscould be made hereto without departing from the spirit and scope of thepresent disclosure. Accordingly, it is intended that the scope of thepresent disclosure be limited not by this detailed description, butrather by the claims appended hereto.

What is claimed is:
 1. A method comprising: providing a data structurefor a region of a document, the data structure including a start value,an end value, and an offset value that define the region within thedocument; and responsive to detection of a modification of contentwithin the region, determining a count of the number of lines of thedocument within the region; adjusting at least one of the start value,the end value, and the offset value of the region to change an area ofthe region based on the count of the number of lines; and pushing arecord of the modification onto a stack of the region in response to themodification of content within the region, the stack configured toreceive elements representative of individual actions to be performed oncontent within the region of the document, so as to enable themodification to be undone or redone in a non-linear fashion.
 2. Themethod of claim 1, wherein the modification results in an addition of atleast one line in the region.
 3. The method of claim 1, wherein themodification results in a deletion of at least one line in the region.4. The method of claim 1, wherein the stack is one of an undo stack or aredo stack.
 5. The method of claim 1, wherein the modification is anundo operation and the stack is a redo stack.
 6. The method of claim 1,wherein the modification is a redo operation and the stack is an undostack.
 7. The method of claim 1, wherein the region is a first region,the method further comprising: responsive to detection of a modificationof content that adds or deletes at least one line within a second regionof the document located above the first region of the document,adjusting the offset value of the first region to change an area of thefirst region based on the modification of content within the secondregion.
 8. The method of claim 1, wherein the modification results in amerging of an adjacent region of the document and the region.
 9. Asystem comprising: a memory; and one or more processors in communicationwith the memory and configured to: provide a data structure for a regionof a document, the data structure including a start value, an end value,and an offset value that define the region within the document; andresponsive to detection of a modification of content within the region,determine a count of the number of lines of the document within theregion; adjust at least one of the start value, the end value, andoffset value of the region to change an area of the region based on thecount of the number of lines; and push a record of the modification ontoa stack of the region in response to the modification of content withinthe region, the stack configured to receive elements representative ofindividual actions to be performed on content within the region of thedocument, so as to enable the modification to be undone or redone in anon-linear fashion.
 10. The system of claim 9, wherein the modificationis an undo operation and the stack is a redo stack.
 11. The system ofclaim 9, wherein the modification is a redo operation and the stack isan undo stack.
 12. The system of claim 9, wherein the modificationresults in an addition of at least one line in the region.
 13. Thesystem of claim 9, wherein the modification results in a deletion of atleast one line in the region.
 14. The system of claim 9, wherein theregion is a first region, the one or more processors further configuredto: responsive to detection of a modification of content that adds ordeletes at least one line within a second region of the document locatedabove the first region of the document, adjust the offset value of thefirst region to change an area of the first region based on themodification of content within the second region.
 15. The system ofclaim 9, wherein the modification results in a merge of an adjacentregion of the document and the region.
 16. A method comprising:providing a first data structure for a first region of a document, thefirst data structure including a start value, an end value, and anoffset value that define the first region within the document; providinga second data structure for a second region of a document below thefirst region, the second data structure including a start value, an endvalue, and an offset value that define the second region within thedocument; and responsive to detection of a modification of contentwithin the first region: determining a count of the number of linesadded or deleted in the first region; adjusting at least one of thestart value and the end value of the first region based on themodification of content within the first region; and adjusting theoffset value of the second region to change an area of the second regionbased on the count of the number of lines added or deleted in the firstregion.
 17. The method of claim 16, further comprising, responsive todetection of the modification of content within the first region,pushing a record of the modification onto a stack of the first region inresponse to the modification of content within the first region, thestack configured to receive elements representative of individualactions to be performed on content within the first region of thedocument, so as to enable the modification to be undone or redone in anon-linear fashion.
 18. The method of claim 17, wherein the stack is anundo stack.
 19. The method of claim 17, wherein the stack is a redostack.
 20. The method of claim 16, wherein the modification results in amerging of the first region and the second region.